Figure 3. Epigenetic reduction of dimensionality of lower lever deterministic networks.

A, epigenetic bridges can cross unconnected or widely dispersed elements of deterministic networks of lower level (e.g. genomics networks) thereby facilitating adaptive evolution on an ecological time scale. B, epigenetic effects (large ellipsoid) of muscle–ossification interface encompass previously unconnected genomic areas to compensate for successive losses of genes under the thermogenesis hypothesis for the origin of birds. UCP1, uncoupling protein 1; Glut4, insulin-responsive glucose transporter. C, epigenetic effects ‘subsample’ elements of distinct behavioural strategies to produce rapid matching of morphs to prevalent contexts without eroding the genetic integration of components of complex behavioural phenotypes in bluebirds. D, epigenetic recruitment and integration of novel pathways of calcium synthesis under stress-induced growth in house finches. BMP, bone morphogenetic protein; OSS, ossification.